Mercury - SpitFire X7 4-Blade Stainless Steel Propeller 13" Diameter x 17" Pitch Right-Hand Rotation 4-Blade Stainless Steel Polished Finish 8M0151362. Overview. There's a certain satisfaction in feeling your boat respond instantly when you push the throttle forward. The Mercury SpitFire X7 13x17 Right-Hand 4-Blade Stainless Steel Propeller (8M0151362) gives you that kind of control-quick, confident, and thrilling. It's light on its feet but solid in its grip, turning every burst of acceleration